Nothing short of caring deeply can cause astronomers to publish such a burst of papers on an as-yet theoretical planet, too distant to have already been captured by our numerous telescope facilities. A recent paper counts twenty two new publications from planetary scientists in 2016, assessing the specific claims of a paper that came out almost exactly a year ago, on the 20th of January, 2016. Over twenty papers in a year is a pretty substantial achievement for any individual object - in fact, off the top of my head, the only other single object that reached those dizzy heights in 2016 is Boyajian’s Star (also known by its technical name KIC 8462852), which you may remember as the alien megastructures star (it was not alien megastructures).

This artists concept contrasts our familiar Earth with the exceptionally strange planet known as 55 Cancri e. While it is only about twice the size of the Earth, NASA's Spitzer Space Telescope has gathered surprising new details about this supersized and superheated world. New observations with Spitzer reveal 55 Cancri e to have a mass 7.8 times and a radius just over twice that of Earth. Those properties place 55 Cancri e in the "super-Earth" class of exoplanets, a few dozen of which have been found. Image credit: NASA/JPL-Caltech/R. Hurt (SSC)

The papers have kept coming, and with each one, the range of options for this planet grow smaller and smaller. Simulations have been run to test how unlikely our observations of the solar system are. If a planet were there, would we expect to see this setup in our solar system? That particular simulation leans towards no - which should make you suspicious of whether we understand the data as well as we would like. More data is being taken to see if the planet’s signature in our view of the solar system is a bias in the way we hunt for these objects.

Scientists, and astronomers are no exception, are cautious creatures. What we are seeing at the moment is a live, highly publicized, discussion on the various merits and demerits of the idea of a ninth, very distant, planet. But each piece of the puzzle, as data is taken and analyzed, takes time to process, time to analyze, and time to figure out how it fits in with everyone else's work. It's a lengthy process, and everyone wants to get their part right. We won't have a final answer on this version of Planet Nine until it is directly discovered or its existence can be entirely ruled out - in either case it will be a few years of work.